1. Field of the Invention
The present invention relates to a generator control device that controls a generator so as to effectively reduce hazardous components of engine exhaust gases.
2. Description of the Related Art
Usually, a vehicle-mounted generator is controlled by controlling its field current according to a battery condition so that the battery does not become over-discharged, as shown in JP-A 2000-4502 or U.S. Pat. No. 6,621,250. Because the generator is driven by an engine, the fuel consumption of the engine increases as the load of the engine becomes heavier. As the engine load increases due to increase in the output electric power of a generator, more hazardous gas components such as NOx component are emitted from the engine.
U.S. Pat. No. 5,336,932A discloses an engine control device to operate a generator only when the fuel consumption can be controlled within a low level. However, it is difficult to limit the hazardous components when a large amount of electric power is required generated.